The most traditional method for calling an elevator is to press a button indicating the direction the passenger is wishing to travel. This is, however, insufficient with the modern elevator systems of today when elevator groups may have a large number of elevators with different properties. For example, in the group there may be express elevators with preselected possible destinations. Such systems typically exist in large buildings with a need for a high capacity elevator system.
The efficiency of the elevator system may be improved by using so called destination control system with possibility to indicate a number of the persons travelling with the person who made an elevator call. An elevator call for a plurality of people is known as a group call. The similar functionality may be done, for example, by requesting each traveler to indicate the destination by themselves. When a plurality of people belonging to the same group presses the button, or a person calling the journey for the complete group indicates the number of travelers, the group controller may allocate the journey efficiently. For example, when there is a group of 16 people and the capacity of the elevator is 16 people, the elevator knows that in order to fit the group to one elevator it must bring an empty elevator. Furthermore, the group controller knows that then the elevator is full and it should not do intermediate stops before the group has reached the desired destination.
The functionality discussed above may be implemented with prioritization algorithms. For example, an elevator call for ten people may be prioritized over an elevator call just for one or longer journeys may be prioritized over short ones.
The problem with the prioritization mentioned above is that persons tend to order journeys for larger groups, for example, because of the prioritization or just for the sake of the convenience of travelling alone or in smaller groups. The same applies to journey lengths, wherein a person may make two elevator calls. The first call is the call for the real journey and the second call is imaginary call, for example, for more people and farther from the calling floor.
Even if the prioritization is not used in all elevator systems they share the same problem as people tend to use same behavior when they do not know for sure if there is prioritization or not. Thus, persons tend to make calls for larger groups or imaginary calls in order to support their own calls. This reduces the capacity of the elevator system as the elevators travel with non-optimal load.
In order to reduce false calls a system with a light port has been used. If an elevator has been called from a floor and nobody steps in the call can be cancelled. The problem with this system is that it only notices the difference between zero and at least one passenger. Thus, it cannot be used for larger groups or imaginary calls. Furthermore, the mechanism does not work if there are more people travelling from the same floor and one person places an imaginary call as others will enter the elevator anyway. Thus, the light port will indicate that at least one person has entered the elevator.
Thus, there is a need for an elevator system facilitating the removal of falsified and imaginary calls. Correspondingly, there is a need for facilitating the removal of accidentally placed incorrect calls.